We are unable to consume ideas because they only exist as a neurological entity. Somebody else can have the same idea or something like it. I have to agree because I have never eaten a dream.
But software is more than an idea or an electronic entity. It is a machine created by a human and the machine has a purpose designed by the creator. The creator wrote many lines of code (a physical entity if you print them out), and then a machine called a compiler turned them into a new machine called an application. This process requires copyright protection in order to reward creators. The argument about copyright protection is "how long?"
BTW I have never consumed a computer manual, because so few are published on rice paper. And I don't think that manuals can be consumed in the same way as electricity or ink. They are like software.